6Pcs wide mouth Mason jar mushroom cultivation lids Two air exchange openings equipped with a 0.22μm PTFE filter, ensuring highly efficient air exchange. 20mm Self Healing Injection Port Autoclavable & reusable, and Stack friendly in Autoclave or high pressure cooker. Food grade mushroom liquid culture Mason jar lids. Highly efficient air exchange, Autoclavable and resuable, Stack friendly in Autoclave or pressure cooker.